Of what use are RCTs?

In this video science philosopher Nancy Cartwright explains why using Randomized Controlled Trials (RCTs) is not at all the “gold standard” that it has lately often been portrayed as. As yours truly has repeatedly argued on this blog (e.g. here and here), RCTs usually do not provide evidence that their results are exportable to other target systems. The almost religious belief with which its propagators portray it, cannot hide the fact that RCTs cannot be taken for granted to give generalizable results. That something works somewhere is no warranty for it to work for us or even that it works generally.